The future of Regina Finn as chief executive of Ofwat was looking increasingly uncertain last night after an extraordinary attack by one of the elders of the water industry.

Ken Harvey, the veteran chairman of Pennon, the South West Water group, yesterday took City analysts unawares with an off-script assault on the regulator’s leadership at the company’s half-year results. Calling the present stand-off between the regulator and water suppliers over the planned introduction of competition “unacceptable”, Mr Harvey demanded change at the top of Ofwat.

Analysts believe that the apparent impasse between Ofwat and the majority of the country’s 22